The skin stratum corneum is quite an important structure for moisture retaining and protecting functions of the skin. Specifically, intercorneocytic lipids form an interkeratinocytic lamellar structure to function like hard cement, which may turn into a skin barrier function. The intercorneocytic lipids comprise lipid components, such as ceramides, cholesterol, fatty acids, etc. and it has been found that ceramides are the most pivotal lipids in the intercorneocytic lipids so as to be contained in the amount of approximately 50% by weight based on the total weight of the intercorneocytic lipids and exert a skin barrier function.
Ceramides constitute lamellar liquid crystalline structures together with cholesterol, fatty acids to form a robust structure offering a skin barrier function. Therefore, impairments in ceramides may weaken a skin barrier function, thereby leading to adverse effects on intrinsic functions of the skin, and resulting in various skin troubles or diseases, such as atopic dermatitis, etc., or aggregating symptoms of the skin troubles or diseases.
In addition, ceramides constituting intercellular lipids are also present in the hair. The stratum corneum of the skin and the cuticle of the hair perform similar functions. The hair cuticle, which is present in the outermost part of the hair, prevents the hair from being damaged and functions as a barrier for protecting the hair from external stimuli. The ceramides exist in the hair cuticles and perform functions of strengthening and protecting internal tissues of the hair.
As ceramides are known to be essential, many cosmetic companies and pharmaceutical companies are focusing on researches for development of products using ceramides. However, since it is practically difficult to obtain naturally occurring ceramides, pseudoceramides, which are structurally and functionally substantially the same with ceramides present in the skin, are being developed. Ceramides currently being applied in Korea on a commercial basis include ceramides extracted from microorganisms (natural ceramides), pseudoceramides developed by Amore Pacific Corporation (Korea) and commercially available under the trade name PC-104 (International Patent Publication No. WO2014-084676), pseudoceramide commercially available from Aekyung Industrial Co., Inc. under the trade name PC-9S (U.S. Pat. No. 6,221,371), etc., which are, however, restricted in general purpose use due to a cost problem arising because of a complicated manufacturing process.
Accordingly, it is highly required to conduct researches into novel pseudoceramide materials, which can be easily prepared to enable general purpose uses and have improved solubility.